// license:BSD-3-Clause
// copyright-holders:Curt Coder
/**********************************************************************
Luxor ABC 1600 Memory Access Controller emulation
**********************************************************************/
/*
TODO:
- segment/page RAM addresses are not correctly decoded, "sas/format/format" can't find the SASI interface because of this
forcetask0 1 t0 0 t1 0 t2 0 t3 0
sega19 0 task 0
sega 000 segd 00 pga 008 pgd 4058 virtual 02c730 (should be 004730)
*/
#include "abc1600mac.h"
//**************************************************************************
// MACROS / CONSTANTS
//**************************************************************************
#define LOG 0
#define A0 BIT(offset, 0)
#define A1 BIT(offset, 1)
#define A2 BIT(offset, 2)
#define A4 BIT(offset, 4)
#define A7 BIT(offset, 7)
#define A8 BIT(offset, 8)
#define X11 BIT(offset, 11)
#define X12 BIT(offset, 12)
#define A17 BIT(offset, 17)
#define A18 BIT(offset, 18)
#define A19 BIT(offset, 19)
#define A10_A9_A8 ((offset >> 8) & 0x07)
#define A2_A1_A0 (offset & 0x07)
#define A1_A2 ((A1 << 1) | A2)
#define A2_A1 ((offset >> 1) & 0x03)
#define FC0 BIT(fc, 0)
#define FC1 BIT(fc, 1)
#define FC2 BIT(fc, 2)
#define PAGE_WP BIT(page_data, 14)
#define PAGE_NONX BIT(page_data, 15)
#define BOOTE BIT(m_task, 6)
#define MAGIC BIT(m_task, 7)
#define READ_MAGIC !MAGIC
//**************************************************************************
// DEVICE DEFINITIONS
//**************************************************************************
const device_type ABC1600_MAC = &device_creator<abc1600_mac_device>;
DEVICE_ADDRESS_MAP_START( map, 8, abc1600_mac_device )
AM_RANGE(0x00000, 0xfffff) AM_READWRITE(read, write)
ADDRESS_MAP_END
static ADDRESS_MAP_START( program_map, AS_PROGRAM, 8, abc1600_mac_device )
ADDRESS_MAP_END
//-------------------------------------------------
// ROM( abc1600_mac )
//-------------------------------------------------
ROM_START( abc1600_mac )
ROM_REGION( 0x4000, "boot", 0 )
ROM_LOAD( "boot 6490356-04.1f", 0x0000, 0x4000, CRC(9372f6f2) SHA1(86f0681f7ef8dd190b49eda5e781881582e0c2a4) )
ROM_REGION( 0x104, "plds", 0 )
ROM_LOAD( "1022 6490351-01.17e", 0x000, 0x104, CRC(5dd00d43) SHA1(a3871f0d796bea9df8f25d41b3169dd4b8ef65ab) ) // MAC register address decoder
ROM_END
//-------------------------------------------------
// rom_region - device-specific ROM region
//-------------------------------------------------
const rom_entry *abc1600_mac_device::device_rom_region() const
{
return ROM_NAME( abc1600_mac );
}
//**************************************************************************
// LIVE DEVICE
//**************************************************************************
//-------------------------------------------------
// abc1600_mac_device - constructor
//-------------------------------------------------
abc1600_mac_device::abc1600_mac_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
: device_t(mconfig, ABC1600_MAC, "ABC 1600 MAC", tag, owner, clock, "abc1600mac", __FILE__),
device_memory_interface(mconfig, *this),
m_space_config("program", ENDIANNESS_LITTLE, 8, 22, 0, *ADDRESS_MAP_NAME(program_map)),
m_rom(*this, "boot"),
m_segment_ram(*this, "segment_ram"),
m_page_ram(*this, "page_ram"),
m_task(0)
{
}
//-------------------------------------------------
// device_start - device-specific startup
//-------------------------------------------------
void abc1600_mac_device::device_start()
{
// get the CPU device
m_cpu = machine().device<m68000_base_device>(m_cpu_tag);
assert(m_cpu != NULL);
// allocate memory
m_segment_ram.allocate(0x400);
m_page_ram.allocate(0x400);
// HACK fill segment RAM or abcenix won't boot
memset(m_segment_ram, 0xcd, 0x400);
// state saving
save_item(NAME(m_ifc2));
save_item(NAME(m_task));
save_item(NAME(m_dmamap));
save_item(NAME(m_cause));
}
//-------------------------------------------------
// device_reset - device-specific reset
//-------------------------------------------------
void abc1600_mac_device::device_reset()
{
// clear task register
m_task = 0;
}
//-------------------------------------------------
// memory_space_config - return a description of
// any address spaces owned by this device
//-------------------------------------------------
const address_space_config *abc1600_mac_device::memory_space_config(address_spacenum spacenum) const
{
return (spacenum == AS_PROGRAM) ? &m_space_config : NULL;
}
//-------------------------------------------------
// get_current_task -
//-------------------------------------------------
int abc1600_mac_device::get_current_task(offs_t offset)
{
int force_task0 = !(m_ifc2 || A19);
int t0 = !(BIT(m_task, 0) || force_task0);
int t1 = !(BIT(m_task, 1) || force_task0);
int t2 = !(BIT(m_task, 2) || force_task0);
int t3 = !(BIT(m_task, 3) || force_task0);
return (t3 << 3) | (t2 << 2) | (t1 << 1) | t0;
}
//-------------------------------------------------
// get_segment_address -
//-------------------------------------------------
offs_t abc1600_mac_device::get_segment_address(offs_t offset)
{
int sega19 = !(!(A8 || m_ifc2) || !A19);
int task = get_current_task(offset);
return (task << 5) | (sega19 << 4) | ((offset >> 15) & 0x0f);
}
//-------------------------------------------------
// get_page_address -
//-------------------------------------------------
offs_t abc1600_mac_device::get_page_address(offs_t offset, UINT8 segd)
{
return ((segd & 0x3f) << 4) | ((offset >> 11) & 0x0f);
}
//-------------------------------------------------
// translate_address -
//-------------------------------------------------
offs_t abc1600_mac_device::translate_address(offs_t offset, int *nonx, int *wp)
{
// segment
offs_t sega = get_segment_address(offset);
UINT8 segd = m_segment_ram[sega];
// page
offs_t pga = get_page_address(offset, segd);
UINT16 page_data = m_page_ram[pga];
offs_t virtual_offset = ((page_data & 0x3ff) << 11) | (offset & 0x7ff);
if (PAGE_NONX)
{
//logerror("Bus error %06x : %06x\n", offset, virtual_offset);
//m_cpu->set_input_line(M68K_LINE_BUSERROR, ASSERT_LINE);
//m_cpu->set_input_line(M68K_LINE_BUSERROR, CLEAR_LINE);
}
*nonx = PAGE_NONX;
*wp = PAGE_WP;
return virtual_offset;
}
//-------------------------------------------------
// read_user_memory -
//-------------------------------------------------
UINT8 abc1600_mac_device::read_user_memory(offs_t offset)
{
int nonx = 0, wp = 0;
offs_t virtual_offset = translate_address(offset, &nonx, &wp);
return space().read_byte(virtual_offset);
}
//-------------------------------------------------
// write_user_memory -
//-------------------------------------------------
void abc1600_mac_device::write_user_memory(offs_t offset, UINT8 data)
{
int nonx = 0, wp = 0;
offs_t virtual_offset = translate_address(offset, &nonx, &wp);
//if (nonx || !wp) return;
space().write_byte(virtual_offset, data);
}
//-------------------------------------------------
// read_supervisor_memory -
//-------------------------------------------------
UINT8 abc1600_mac_device::read_supervisor_memory(address_space &space, offs_t offset)
{
UINT8 data = 0;
if (!A2 && !A1)
{
// _EP
data = page_r(space, offset);
}
else if (!A2 && A1 && A0)
{
// _ES
data = segment_r(space, offset);
}
else if (A2 && A1 && A0)
{
// _CAUSE
data = cause_r(space, offset);
}
return data;
}
//-------------------------------------------------
// write_supervisor_memory -
//-------------------------------------------------
void abc1600_mac_device::write_supervisor_memory(address_space &space, offs_t offset, UINT8 data)
{
if (!A2 && !A1)
{
// _WEP
page_w(space, offset, data);
}
else if (!A2 && A1 && A0)
{
// _WES
segment_w(space, offset, data);
}
else if (A2 && !A1 && A0)
{
// W(C)
task_w(space, offset, data);
}
}
//-------------------------------------------------
// get_fc -
//-------------------------------------------------
int abc1600_mac_device::get_fc()
{
UINT16 fc = m_cpu->get_fc();
m_ifc2 = !(!(MAGIC || FC0) || FC2);
return fc;
}
//-------------------------------------------------
// read -
//-------------------------------------------------
READ8_MEMBER( abc1600_mac_device::read )
{
int fc = get_fc();
UINT8 data = 0;
if (!BOOTE && !A19 && !A18 && !A17)
{
// _BOOTCE
data = m_rom->base()[offset & 0x3fff];
}
else if (A19 && !m_ifc2 && !FC1)
{
data = read_supervisor_memory(space, offset);
}
else
{
data = read_user_memory(offset);
}
return data;
}
//-------------------------------------------------
// write -
//-------------------------------------------------
WRITE8_MEMBER( abc1600_mac_device::write )
{
int fc = get_fc();
if (A19 && !m_ifc2 && !FC1)
{
write_supervisor_memory(space, offset, data);
}
else
{
write_user_memory(offset, data);
}
}
//-------------------------------------------------
// cause_r -
//-------------------------------------------------
READ8_MEMBER( abc1600_mac_device::cause_r )
{
/*
bit description
0 RSTBUT
1 1
2 DMAOK
3 X16
4 X17
5 X18
6 X19
7 X20
*/
UINT8 data = 0x02;
// DMA status
data |= m_cause;
machine().watchdog_reset();
return data;
}
//-------------------------------------------------
// task_w -
//-------------------------------------------------
WRITE8_MEMBER( abc1600_mac_device::task_w )
{
/*
bit description
0 TASKD0* (inverted SEGA5)
1 TASKD1* (inverted SEGA6)
2 TASKD2* (inverted SEGA7)
3 TASKD3* (inverted SEGA8)
4
5
6 BOOTE*
7 MAGIC*
*/
m_task = data ^ 0xff;
if (LOG) logerror("%s: %06x Task %u BOOTE %u MAGIC %u\n", machine().describe_context(), offset, get_current_task(offset), BOOTE, MAGIC);
}
//-------------------------------------------------
// segment_r -
//-------------------------------------------------
READ8_MEMBER( abc1600_mac_device::segment_r )
{
/*
bit description
0 SEGD0
1 SEGD1
2 SEGD2
3 SEGD3
4 SEGD4
5 SEGD5
6 SEGD6
7 READ_MAGIC
*/
offs_t sega = get_segment_address(offset);
UINT8 segd = m_segment_ram[sega];
return (READ_MAGIC << 7) | (segd & 0x7f);
}
//-------------------------------------------------
// segment_w -
//-------------------------------------------------
WRITE8_MEMBER( abc1600_mac_device::segment_w )
{
/*
bit description
0 SEGD0
1 SEGD1
2 SEGD2
3 SEGD3
4 SEGD4
5 SEGD5
6 SEGD6
7 0
*/
offs_t sega = get_segment_address(offset);
m_segment_ram[sega] = data & 0x7f;
if (LOG) logerror("%s: %06x Task %u Segment %03x : %02x\n", machine().describe_context(), offset, get_current_task(offset), sega, data);
}
//-------------------------------------------------
// page_r -
//-------------------------------------------------
READ8_MEMBER( abc1600_mac_device::page_r )
{
/*
bit description
0 X11
1 X12
2 X13
3 X14
4 X15
5 X16
6 X17
7 X18
8 X19
9 X20
10 X20
11 X20
12 X20
13 X20
14 _WP
15 NONX
*/
// segment
offs_t sega = get_segment_address(offset);
UINT8 segd = m_segment_ram[sega];
// page
offs_t pga = get_page_address(offset, segd);
UINT16 pgd = m_page_ram[pga];
UINT8 data = 0;
if (A0)
{
data = pgd & 0xff;
}
else
{
int x20 = BIT(pgd, 9);
data = (pgd >> 8) | (x20 << 2) | (x20 << 3) | (x20 << 4) | (x20 << 5);
}
return data;
}
//-------------------------------------------------
// page_w -
//-------------------------------------------------
WRITE8_MEMBER( abc1600_mac_device::page_w )
{
/*
bit description
0 X11
1 X12
2 X13
3 X14
4 X15
5 X16
6 X17
7 X18
8 X19
9 X20
10
11
12
13
14 _WP
15 NONX
*/
// segment
offs_t sega = get_segment_address(offset);
UINT8 segd = m_segment_ram[sega];
// page
offs_t pga = get_page_address(offset, segd);
if (A0)
{
m_page_ram[pga] = (m_page_ram[pga] & 0xff00) | data;
}
else
{
m_page_ram[pga] = ((data & 0xc3) << 8) | (m_page_ram[pga] & 0xff);
}
if (LOG) logerror("%s: %06x Task %u Segment %03x Page %03x : %02x -> %04x\n", machine().describe_context(), offset, get_current_task(offset), sega, pga, data, m_page_ram[pga]);
}
//-------------------------------------------------
// get_dma_address -
//-------------------------------------------------
offs_t abc1600_mac_device::get_dma_address(int index, UINT16 offset)
{
// A0 = DMA15, A1 = BA1, A2 = BA2
UINT8 dmamap_addr = index | BIT(offset, 15);
UINT8 dmamap = m_dmamap[dmamap_addr];
m_cause = (dmamap & 0x1f) << 3;
return ((dmamap & 0x1f) << 16) | offset;
}
//-------------------------------------------------
// dma_mreq_r - DMA memory read
//-------------------------------------------------
UINT8 abc1600_mac_device::dma_mreq_r(int index, UINT16 offset)
{
offs_t virtual_offset = get_dma_address(index, offset);
return space().read_byte(virtual_offset);
}
//-------------------------------------------------
// dma_mreq_w - DMA memory write
//-------------------------------------------------
void abc1600_mac_device::dma_mreq_w(int index, UINT16 offset, UINT8 data)
{
offs_t virtual_offset = get_dma_address(index, offset);
space().write_byte(virtual_offset, data);
}
//-------------------------------------------------
// dma_iorq_r - DMA I/O read
//-------------------------------------------------
UINT8 abc1600_mac_device::dma_iorq_r(int index, UINT16 offset)
{
offs_t virtual_offset = 0x1fe000 | get_dma_address(index, offset);
return space().read_byte(virtual_offset);
}
//-------------------------------------------------
// dma_iorq_w - DMA I/O write
//-------------------------------------------------
void abc1600_mac_device::dma_iorq_w(int index, UINT16 offset, UINT8 data)
{
offs_t virtual_offset = 0x1fe000 | get_dma_address(index, offset);
space().write_byte(virtual_offset, data);
}
//-------------------------------------------------
// dmamap_w - DMA map write
//-------------------------------------------------
WRITE8_MEMBER( abc1600_mac_device::dmamap_w )
{
/*
bit description
0 X16
1 X17
2 X18
3 X19
4 X20
5
6
7 _R/W
*/
if (LOG) logerror("DMAMAP %u %02x\n", offset & 7, data);
m_dmamap[offset & 7] = data;
}